diff --git a/core/SConscript.firmware b/core/SConscript.firmware
index 93ce77eb3d..43d23d0972 100644
--- a/core/SConscript.firmware
+++ b/core/SConscript.firmware
@@ -662,9 +662,10 @@ if FROZEN:
             SOURCE_PY.extend(Glob(SOURCE_PY_DIR + 'apps/nem/*/*.py'))
             SOURCE_PY.extend(Glob(SOURCE_PY_DIR + 'trezor/enums/NEM*.py'))
 
-        SOURCE_PY.extend(Glob(SOURCE_PY_DIR + 'apps/nostr/*.py'))
-        SOURCE_PY.extend(Glob(SOURCE_PY_DIR + 'apps/nostr/*/*.py'))
-        SOURCE_PY.extend(Glob(SOURCE_PY_DIR + 'trezor/enums/Nostr*.py'))
+        if PYOPT == '0':
+            SOURCE_PY.extend(Glob(SOURCE_PY_DIR + 'apps/nostr/*.py'))
+            SOURCE_PY.extend(Glob(SOURCE_PY_DIR + 'apps/nostr/*/*.py'))
+            SOURCE_PY.extend(Glob(SOURCE_PY_DIR + 'trezor/enums/Nostr*.py'))
 
         SOURCE_PY.extend(Glob(SOURCE_PY_DIR + 'apps/ripple/*.py'))
         SOURCE_PY.extend(Glob(SOURCE_PY_DIR + 'trezor/enums/Ripple*.py'))
diff --git a/core/SConscript.unix b/core/SConscript.unix
index 00227af2dd..4e50b0d59c 100644
--- a/core/SConscript.unix
+++ b/core/SConscript.unix
@@ -721,9 +721,10 @@ if FROZEN:
             SOURCE_PY.extend(Glob(SOURCE_PY_DIR + 'apps/nem/*/*.py'))
             SOURCE_PY.extend(Glob(SOURCE_PY_DIR + 'trezor/enums/NEM*.py'))
 
-        SOURCE_PY.extend(Glob(SOURCE_PY_DIR + 'apps/nostr/*.py'))
-        SOURCE_PY.extend(Glob(SOURCE_PY_DIR + 'apps/nostr/*/*.py'))
-        SOURCE_PY.extend(Glob(SOURCE_PY_DIR + 'trezor/enums/Nostr*.py'))
+        if PYOPT == '0':
+            SOURCE_PY.extend(Glob(SOURCE_PY_DIR + 'apps/nostr/*.py'))
+            SOURCE_PY.extend(Glob(SOURCE_PY_DIR + 'apps/nostr/*/*.py'))
+            SOURCE_PY.extend(Glob(SOURCE_PY_DIR + 'trezor/enums/Nostr*.py'))
 
         SOURCE_PY.extend(Glob(SOURCE_PY_DIR + 'apps/ripple/*.py'))
         SOURCE_PY.extend(Glob(SOURCE_PY_DIR + 'trezor/enums/Ripple*.py'))
diff --git a/core/src/apps/nostr/__init__.py b/core/src/apps/nostr/__init__.py
index 98377d3a9c..cd0a89a447 100644
--- a/core/src/apps/nostr/__init__.py
+++ b/core/src/apps/nostr/__init__.py
@@ -1,3 +1,8 @@
+if not __debug__:
+    from trezor import utils
+
+    utils.halt("Disabled in production mode")
+
 from apps.common.paths import PATTERN_BIP44
 
 CURVE = "secp256k1"
diff --git a/core/src/apps/workflow_handlers.py b/core/src/apps/workflow_handlers.py
index af8460791b..c7ff7ba477 100644
--- a/core/src/apps/workflow_handlers.py
+++ b/core/src/apps/workflow_handlers.py
@@ -106,11 +106,15 @@ def _find_message_handler_module(msg_type: int) -> str:
     if msg_type == MessageType.GetFirmwareHash:
         return "apps.misc.get_firmware_hash"
 
-    # nostr
-    if msg_type == MessageType.NostrGetPubkey:
-        return "apps.nostr.get_pubkey"
-    if msg_type == MessageType.NostrSignEvent:
-        return "apps.nostr.sign_event"
+    # When promoting the Nostr app to production-level
+    # and removing the "if" guard don't forget to also remove
+    # the corresponding guards (PYOPT == '0') in Sconscript.*
+    if __debug__:
+        # nostr
+        if msg_type == MessageType.NostrGetPubkey:
+            return "apps.nostr.get_pubkey"
+        if msg_type == MessageType.NostrSignEvent:
+            return "apps.nostr.sign_event"
 
     if not utils.BITCOIN_ONLY:
         if msg_type == MessageType.SetU2FCounter: